CN205443958U - Composite truss support of big cantilever bent cap - Google Patents

Abstract

A composite truss support for a large cantilever cover beam, which adopts a panel lattice composite truss support. The whole support system is mainly divided into five modules: lower legs, composite truss, distribution beam, sand box and tripod bracket. Channel steel and bolts connect the 5 modules sequentially from bottom to top to form a whole. The lower 2 modules are composed of 4 lattice columns on the platform. The beam between the lower column and the upper column is the lower beam, and the upper beam is upper According to the position of the vertical rods of the bracket, the distribution beam used to support the triangular bracket of the cover beam and set up the working platform is arranged; the square sand box is arranged between the distribution beam and the triangular bracket, and the diagonal brace connects the ends of the upper beam and the lower beam with pins. At the same time, the front and rear diagonal braces are connected by horizontal cross-links, and the cross-beam cross-links and diagonal braces are welded between the upper beams and the lower beams. The utility model effectively solves the dependence of the support on the site and the foundation, and has the characteristics of simple structure, fast disassembly and assembly speed, high safety in actual operation, and recyclable utilization.

Description

A Composite Truss Support for Large Cantilever Cover Beam

technical field

The utility model relates to the field of bridge engineering construction, in particular to a design of a combined truss support for a large cantilever cover beam constructed in a weak foundation and a construction method thereof.

Background technique

In the increasingly developed transportation network, due to the increase in transportation volume year by year, the transportation network is constantly improving, and the number of new lines is increasing. In the overall linear design of urban viaducts, in order to overcome the complex ground conditions and the influence of traffic under the bridge, the structural form combining cantilever cap girder piers and prestressed prefabricated small box girders is often used. As far as expressways are concerned, there are relatively many cylindrical piers with small overhangs at both ends, and this form is relatively mature in design and construction technology. In recent years, with the continuous improvement of expressway design, there are more and more long cantilever prestressed cap beam projects. There is no mature experience in the relevant construction technology in China for reference, and the relevant construction technology needs to be studied urgently. The foundation must be hardened for construction using the conventional support method, thus increasing the construction cost.

Utility model content

The utility model provides a combined truss support for a large cantilever cover beam constructed in a weak foundation and a construction method thereof, which effectively solves the dependence of the support on the site and the foundation. The characteristics of ground hardening treatment, high safety in actual operation, and recyclability greatly save costs.

The technical scheme that the utility model takes:

A composite truss support for a large cantilever cover beam, which adopts a panel lattice composite truss support. The whole support system is mainly divided into five modules: lower legs, composite truss, distribution beam, sand box and tripod bracket. Channel steel and bolts connect the 5 modules sequentially from bottom to top to form a whole. The lower 2 modules are composed of 4 lattice columns on the platform. The columns are divided into lower columns and upper columns. The beam is the lower beam, and the beam above the upper column is the upper beam. The upper beam is welded with 40 double I-beams. The upper beam is arranged according to the position of the vertical rod of the bracket to support the triangular bracket of the cover beam and set the distribution of the working platform. Beam; the square sand box is set between the distribution beam and the triangular bracket. Above the triangular bracket is the bottom formwork of the cover beam. The ends of the upper beam and the lower beam are hinged with pins through diagonal braces. At the same time, between the front and rear diagonal braces They are all connected by horizontal cross-links, and scissors braces are set, and cross-beam cross-links and diagonal braces are welded between the front and rear beams and between the lower beams.

The distribution beam is made of 18a I-beam

The lower column adopts 32c channel steel combination welding, and the upper column adopts 22b channel steel combination welding, and the front and rear columns and the lower column are connected with [14 channel steel horizontal column cross connection.

The plane size of the sand box is 35cm×35cm, and the adjustable height range is 22-32cm.

Described diagonal brace, cross-link and scissors brace, lower beam and cross-beam cross-link and diagonal brace are [28 double channel steel.

A construction method for a composite truss support of a large cantilever cap beam, comprising the following steps:

(1) Cleaning the platform: before installing the bracket, clean up the sundries on the top surface of the platform to ensure that the lower legs of the bracket can directly contact with the platform and ensure the stable force of the bracket;

(2) Determining the height of the support: determine the combination scheme that needs to be installed with outriggers according to the design height of the pier column. The outriggers have three models with a height of 2m, 1m and 0.3m;

(3) Installation of lower outriggers: According to the outrigger combination plan determined by calculation, first install outriggers with a height of 2m, and then install outriggers with a height of 1m and 0.3m when the remaining height is less than 2m. On the pier column, fine-tune its plane position. After the position is determined, use wooden wedges to insert and fix between the outrigger and the pier column, and connect the upper and lower outriggers with bolts;

(4) Composite truss installation: hoist a piece of pre-assembled composite truss onto the outrigger with a truck crane, and temporarily fix it with the pier column with a chain hoist. Use channel steel and scissors braces to connect and fix the two combined trusses.

(5) Distribution beam installation: The distribution beam on the upper beam is placed on each vertical support of the triangular bracket, 3 pieces are arranged side by side, each distribution beam is 4.5m long, and the Φ25 fine-rolled thread is used between the distribution beam and the upper beam The steel is matched with [10 channel steel platen for locking.

(6) Install the sand box: The installation position of the sand box is set according to the drawings to prevent the sand box from slipping. Use L50×50 angle steel welding positioning slots on the distribution beam, and put the sand box into the positioning slots.

(7) Laying operation platform: For the convenience of construction and to ensure the safety of construction, 5cm thick wooden boards are laid across the bridge on the distribution beam as a construction platform, and short steel bars are welded at both ends of the distribution beam. After the distribution beam is laid, insert steel pipes and steel pipes The height is 1.5m, and a horizontal bar is set every 30cm in the horizontal direction, and the outer side of the railing is surrounded by a protective net.

(8) Install the tripod: In order to speed up the construction, the lower support of the bottom formwork of the cover beam adopts [14 channel steel double-leg combined welding trusses. Pull space. Single-piece hoisting during installation, after the two pieces are all in place, [14 channel steel is used as scissors brace and beam, and the position is set at the truss pole and connected by pins.

The beneficial effects of the utility model are:

(1) The composite truss is used for construction, and the lower column stands directly on the cap platform without foundation treatment.

(2) Because there is no need for foundation treatment, it not only saves costs, but also shortens the construction period of the cap beam.

(3) The truss components used in construction can be assembled on site, and then modularized and disassembled, which greatly improves the construction speed.

(4) The support and pier columns are bound through cross-connections, so the overall stability of the structure is good and the safety factor is high.

(5) The entire support system is made of rigid materials and is rigidly connected, and supported on the platform, so the entire support system has no settlement after installation.

(6) The bracket is processed into a modular form, which can be applied after adjusting the height of the outriggers for pier columns of different heights.

(7) When using this bracket system for construction, it only needs to be equipped with a 25t truck crane and 2 to 4 workers, saving labor.

(8) The bracket can be recycled, and the turnover is convenient.

Description of drawings

Figure 1 is a schematic diagram of the overall front elevation of the composite truss support system of the present invention after erection.

Fig. 2 is a schematic diagram of locking and installation of the upper beam distribution beam of the composite truss support of the present invention.

Fig. 3 is a schematic diagram of installation of legs of the combined truss support system of the present invention.

Among them: 1—cap; 2—column cross connection; 3—pier column; 4—cover beam bottom mold; 5—lower column; 6—lower beam; 7—pin; 8—beam cross connection and diagonal brace; 9 — distribution beam; 10 — diagonal brace; 11 — upper column; 12 — cross connection; 13 — scissors brace; 14 — upper beam; 15 — sand box; 16 — triangular bracket; ;: 19—nut; 20—wooden wedge.

detailed description

The utility model is described in detail below in conjunction with accompanying drawing and specific embodiment.

As shown in accompanying drawing 1, a composite truss support of a large cantilever cover beam of the utility model constructed in a weak foundation, the composite truss support system adopts the panel lattice type combined truss support method, and the whole support system is mainly divided into There are 165 modules including lower outriggers, composite trusses, distribution beams 9, sand boxes 15 and tripod brackets. When installing, use channel steel and bolts to connect the 5 modules from bottom to top to form a whole. 1 is composed of 4 lattice columns, the columns are divided into lower column 5 and upper column 11, the lower column 5 is welded by 32c channel steel combination, the upper column 11 is welded by 22b channel steel combination, and [14 channel steel horizontal column is used between the columns The horizontal connection 2 is connected, the beam between the lower column 5 and the upper column 11 is the lower beam 6, the beam above the upper column 11 is the upper beam 14, the upper beam 14 is welded with 40 double I-beams, and the upper beam 14 is vertically pressed by the bracket. Arrange the distribution beam 9 made of 18a I-beam for supporting the cover beam triangular bracket 16 and setting the working platform to the position of the bar; Square sand box 15, the plane size of sand box 15 is 35cm × 35cm, and the adjustable height range is 22 to 32cm; the top of the triangle bracket 16 is the cover beam bottom mold 4, in order to prevent the end part of the upper beam 14 from being too large, use [ 28 double-channel steel diagonal braces 10 hinge the upper beam 14 and [28 double-channel steel lower beam 6 ends with pins 7, and simultaneously connect the front and rear diagonal braces 10 with [28 channel steel horizontal cross-links 12, and Scissor braces 13 are set, and welding [28 channel steel beam cross-links and diagonal braces 8 between the beams on the front and rear surfaces and between the lower beams.

A construction method for a composite truss support of a large cantilever cap beam constructed in a weak foundation, comprising the following steps:

(1) Cleaning the platform: Before the bracket is installed, the sundries on the top surface of the platform 1 must be cleaned to ensure that the legs of the bracket can directly contact with the platform 1 and ensure that the support is stable under force.

(2) Determining the height of the support: According to the design height of the pier column 3, determine the combination scheme that needs to be installed with outriggers. The outriggers have three models with a height of 2m, 1m and 0.3m.

(3) Installation of lower outriggers: According to the outrigger combination plan determined by calculation, first install outriggers with a height of 2m, and then install outriggers with a height of 1m and 0.3m when the remaining height is less than 2m. When installing, use a car crane to set the outriggers On the pier column 3, fine-tune its plane position. After the position is determined, use wooden wedges to insert and fix between the outrigger and the pier column 3. As shown in Figure 3, the upper and lower sections of the outriggers are connected with bolts.

(4) Composite truss installation: hoist a piece of pre-assembled composite truss onto the outrigger with a truck crane, temporarily fix it with the pier column 3 with a chain block, and wait until all the two composite trusses are hoisted to the outrigger , use channel steel and scissors support 13 to connect and fix the two composite trusses.

(5) Distribution beam installation: the distribution beam 9 on the upper beam 14 is placed on each vertical support of the triangular bracket 16, 3 in a row, and each distribution beam 9 is 4.5m long. In order to ensure the overall stability of the support, the distribution beam 9 and the upper beam 14 are locked with Φ25 finish-rolled rebar 17 and [10 channel steel platen 18, as shown in Figure 2.

(6) Install the sand box: The installation position of the sand box 15 is set according to the drawings. In order to prevent the sand box 15 from sliding sideways, use L50×50 angle steel welding positioning slots on the distribution beam 9, and put the sand box 15 into the positioning slots.

(7) Lay the operation platform: for the convenience of construction and to ensure the safety of construction, a 5cm thick plank is laid on the distribution beam 9 as a construction platform, and short steel bars are welded at both ends of the distribution beam. After the distribution beam 9 is laid, the steel pipes are inserted. , the height of the steel pipe is 1.5m, and a horizontal bar is set every 30cm in the horizontal direction, and the outer side of the railing is surrounded by a protective net.

(8) Install the tripod: In order to speed up the construction, the 4 lower brackets of the bottom formwork of the cover beam adopt [14 channel steel double-leg combined welding trusses. Due to the tension of the lower anchor groove of the cover beam, two pieces of brackets are used for each side flange, and the middle is reserved. Tensile space. Single-piece hoisting during installation, after the two pieces are all in place, [14 channel steel is used as scissors brace and beam, the position is set at the truss pole, and the pin 7 is used to connect.

Claims (5)

1. null1. the composite roof truss support of a great cantilever bent cap，It is characterized in that，Use batten plate lattice composite roof truss support，Whole strutting system is broadly divided into lower supporting leg、Composite roof truss、Distribution beam (9)、Sandbox (15) and (16) 5 modules of three footrest framves，Utilize channel-section steel and bolt that 5 modules are in turn connected into an entirety from down to up during installation，2 modules are made up of 4 lattice columns on cushion cap (1) below，Column divides lower pillar stand (5) and upper pillar stand (11)，Crossbeam between lower pillar stand (5) and upper pillar stand (11) is sill (6)，Upper pillar stand (11) crossbeam above is entablature (14)，Entablature (14) uses 40 pairs of I-steel assembly weldings，Lay for supporting bent cap shelf bracket and arranging the distribution beam (9) of work platforms by support vertical bar position on entablature (14)；Square sandbox (15) is arranged between distribution beam (9) and shelf bracket (16), shelf bracket (16) is arranged above bent cap bed die (4), entablature (14) is hinged with pin (7) by diagonal brace (10) with sill (6) termination, all connect with horizontal horizontal-associate (12) between front-back diagonal brace (10) simultaneously, and bridging (13) is set, welding beam horizontal-associate and diagonal brace (8) between front-back entablature and between sill.
2. The composite roof truss support of great cantilever bent cap the most according to claim 1, it is characterised in that described distribution beam (9) is made up of 18a I-steel.
3. The composite roof truss support of great cantilever bent cap the most according to claim 1, it is characterized in that, described lower pillar stand (5) uses 32c channel-section steel Combination Welding, upper pillar stand (11) uses 22b channel-section steel Combination Welding, uses [14 channel-section steels transverse upright horizontal-associate (2) connections between front-back upper pillar stand and between lower pillar stand.
4. The composite roof truss support of great cantilever bent cap the most according to claim 1, it is characterised in that described sandbox (15) planar dimension is 35cm × 35cm, regulation altitude range is 22～32cm.
5. The composite roof truss support of great cantilever bent cap the most according to claim 1, it is characterized in that, described diagonal brace (10), horizontal-associate (12) and bridging (13), sill (6) and crossbeam horizontal-associate and diagonal brace (8) are [28 double flute steel.